scholarly journals Determination of Acetochlor in Technical and Formulated Products by Capillary Gas Chromatography

2001 ◽  
Vol 84 (2) ◽  
pp. 317-322
Author(s):  
Bobbi B Kahn ◽  
David F Tomkins
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Method Development ◽  
Internal Standard ◽  
Test Sample ◽  
Weight Percent ◽  
Flame Ionization ◽  
Relative Standard ◽  
Data Points

Abstract A peer-verified gas chromatographic (GC) method is presented for the weight percent (wt %) determination of acetochlor herbicide in technical and formulated products. During method development, the method was found to be rugged by the Youden Ruggedness Test. Two laboratories with experience in the wt % determination of acetochlor in various matrixes participated in this study. Each laboratory received 10 blind duplicate test samples of the following 5 matrixes: one acetochlor technical and 4, different, emulsifiable concentrate (EC) formulations—Harness® EC (MON 5841), Harness ® Export/Fist (MON 8435), Surpass® EC (HF), and Surpass ® EC (LF). Each participant was asked to make duplicate weighings of each of the test samples and to inject each test sample solution twice. All test samples were analyzed on the same day, and 8 data points (replicates) per matrix were obtained. The test samples were dissolved in acetone that contained dipentyl phthalate as an internal standard. They were analyzed by GC on a 15 m capillary column by using split injection and a flame ionization detector. Acetochlor (wt %) was determined by comparing the ratios of peak area of acetochlor/peak area of dipentyl phthalate internal standard obtained for the test sample and calibration solutions. Repeatability of the method, expressed as the within-laboratory (between replicates) relative standard deviation (RSDr), was found to be 0.09–0.77% for the 5 matrixes. Reproducibility of the method, expressed as the within-test sample relative standard deviation (RSDR), was found to be 0.18–0.78% for the 5 matrixes.

scholarly journals Determination of 1,3-Dichloropropanol in Soy Sauce and Related Products by Headspace Gas Chromatography with Mass Spectrometric Detection: Interlaboratory Study

2005 ◽  
Vol 88 (5) ◽  
pp. 1404-1412 ◽  
Author(s):  
Sarah Hasnip ◽  
Colin Crews ◽  
Nicholas Potter ◽  
Paul Brereton ◽  
Henri Diserens ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Internal Standard ◽  
Mass Spectrometric ◽  
Soy Sauce ◽  
Headspace Gas Chromatography ◽  
Relative Standard ◽  
Headspace Gas

Abstract An interlaboratory study was performed to evaluate the effectiveness of a headspace gas chromatography (GC) method for the determination of 1,3-dichloro-propan-2-ol (1,3-DCP) in soy sauce and related products at levels above 5 ng/g. The test portion is mixed with an internal standard (d5-1,3-DCP) and ammonium sulfate in a sealed headspace vial. After achieving equilibrium, the headspace is sampled either by gas-tight syringe or solid-phase microextraction (SPME) and analyzed by GC with mass spectrometric detection. 1,3-DCP is detected in the selected-ion mode (monitoring m/z 79 and 81 for 1,3-DCP and m/z 82 for the deuterated internal standard) and quantified by measurement against standards. Test materials comprising soy, dark soy, mushroom soy, and teriyaki sauces, both spiked and naturally contaminated, were sent to 9 laboratories in Europe, Japan, and the United States; of these, 5 used SPME and 4 used syringe headspace analysis. Test portions were spiked at 5.0, 10.0, 20.0, 100.0, and 500.0 ng/g. The average recovery for spiked blank samples was 108% (ranging from 96–130%). Based on results for spiked samples (blind pairs at 5, 10, 20, 100, and 500 ng/g) as well as a naturally contaminated sample (split-level pair at 27 and 29 ng/g), the relative standard deviation for repeatability (RSDr) ranged from 2.9–23.2%. The relative standard deviation for reproducibility (RSDR) ranged from 20.9–35.3%, and HorRat values of between 1.0 and 1.6 were obtained.

scholarly journals UV Spectrophotometric Method Development and Validation of Fimasartan Drug and Its Tablet Formulation

1970 ◽  
Vol 7 (5) ◽  
pp. 25-29
Author(s):  
Kaushik S Agrawal ◽  
Lokesh R Gandhi ◽  
Nitin S. Bhajipale S Bhajipale3
Keyword(s):  
Standard Deviation ◽  
Quantitative Determination ◽  
Relative Standard Deviation ◽  
Spectrophotometric Method ◽  
Method Development ◽  
Cost Effective ◽  
Tablet Formulation ◽  
Relative Standard ◽  
Bulk Drug

A novel, safe and sensitive method of Spectrophotometric estimation in UV - region has been developed for the assay of Fimasartan in its tablet formulation. The present study was undertaken to develop and validate a simple, accurate, precise, reproducible and cost effective UV spectrophotometric method for the estimation of Fimasartan bulk and pharmaceutical formulation. The method have been developed and validated for the assay of Fimasartan using Methanol as diluent. Absorption maximum (λmax) of the drug was found to be 240nm. The quantitative determination of the drug was carried out at 240nm. The method was shown linear in the mentioned concentrations having correlation coefficient R2 of 0.999. The recovery values for Fimasartan ranged from 98.74% to 99.23%.The Percent Relative Standard Deviation of interday and intraday was 0.85% and 0.75% respectively. All the parameters of the analysis were chosen according to the International Conference on Harmonisation guideline and validated statistically using Relative Standard Deviation and Percent Relative Standard Deviation. Hence, proposed method was precise, accurate and cost effective. This method could be applicable for quantitative determination of the bulk drug as well as dosage formulation.   KEY WORDS: 

Gas-Liquid Chromatographic Determination of Fluchloralin in Formulations

1977 ◽  
Vol 60 (5) ◽  
pp. 1145-1147
Author(s):  
Gregory S Grimes
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Reference Standard ◽  
Relative Standard ◽  
Liquid Chromatographic Determination ◽  
Standard Solution ◽  
Liquid Chromatographic

Abstract A gas-liquid chromatographic (GLC) method has been developed that is precise, rapid, simple, and specific for fluchloralin in emulsifiable liquid formulation. Sample and reference standard are weighed, internal standard solution is added, and an aliquot of the mixture is injected onto the chromatographic column. Fluchloralin gives a sharp symmetrical peak at about 5.4 min. The internal standard has a broader symmetrical peak at about 6.9 min. The relative standard deviation for 21 consecutive injections of the standard solution was 0.3773%. The method was compared with the official GLC method, 6.210–6.215, for the structurally similar trifluralin. Fluchloralin gave a sharp symmetrical peak at about 8.5 min; the internal standard had a sharp symmetrical peak at about 9.2 min. The relative standard deviation of 21 consecutive injections of reference standard solution was 0.6988%. Comparison of the variances of the 2 methods by the F-test at the 99% confidence level showed that the proposed method demonstrated substantially better precision.

scholarly journals Determination of ß-Glucan in Barley and Oats by Streamlined Enzymatic Method: Summary of Collaborative Study

1997 ◽  
Vol 80 (3) ◽  
pp. 580-583 ◽  
Author(s):  
Barry V Mccleary ◽  
David C Mugford ◽  
M C Camire ◽  
T S Gibson ◽  
K Harrigan ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Glucose Oxidase ◽  
Relative Standard Deviation ◽  
Collaborative Study ◽  
Test Sample ◽  
Enzymatic Method ◽  
Relative Standard ◽  
Free Glucose ◽  
Flour Sample

Abstract A collaborative study was conducted involving 8 laboratories (including the authors’ laboratories) to validate the streamlined enzymatic method for determination of ß-D-glucan in barley and oats. In the method, the flour sample is cooked to hydrate and gelatinize ß-glucan, which is subsequently hydrolyzed to soluble fragments with the lichenase enzyme. After volume and pH adjustments and filtration, the solution is treated with ß-glucosidase, which hydrolyzes ß-gluco-oligosaccharides to D-glucose. D-Glucose is measured with glucose oxidase-peroxidase reagent. Other portions of lichenase hydrolysate are treated directly with glucose oxidase-peroxidase reagent to measure free glucose in test sample. If levels of free glucose are high, the sample is extracted first with 80% ethanol. For all samples analyzed, the repeatability relative standard deviation (RSDr) values ranged from 3.1 to 12.3% and the reproducibility relative standard deviation (RSDR) values ranged from 6.6 to 12.3%. The streamlined enzymatic method for determination of ß-D-glucan in barley and oats has been adopted first action by AOAC INTERNATIONAL.

Determination of Optimum Data Points for Scaling Factor Determination

2007 ◽  
Author(s):  
Michael Dennis T. Fernandez ◽  
Sang Chul Lee ◽  
Kun Jai Lee
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Scaling Factor ◽  
Published Data ◽  
Optimum Number ◽  
Scaling Factors ◽  
Relative Standard ◽  
Data Points ◽  
The Cost

Scaling factors are calculated based on a database from radiochemical analyses of representative waste samples. Several data points are needed to derive a reliable scaling factor. The more the number of data points, the better is the correlation, but more costly because of number of needed radiochemical analyses. Therefore, optimization of data points should be considered to minimize the cost without compromising reliability and prediction of the scaling factor. Scaling factors for Ni-63, Sr-90, and C-14 were calculated using Co-60 and Cs-137 as Key nuclides based on the published data in EPRI-4037. Correlation coefficient, percent error and relative standard deviation were plotted against the number of data points used in the estimation of scaling factor. The optimum number of data points was obtained to where there was no significant improvement in the statistical uncertainties by using additional samples. Even though non-segregated (all data points) has greater effect in calculating scaling factor because of its more data points, this study showed that even segregated data points can also give good DTM characterization.

An Automated Procedure for the Determination of Ammonia in Tobacco

1972 ◽  
Vol 6 (4) ◽  
Author(s):  
P.F. Collins ◽  
W.W. Lawrence ◽  
J.F. Williams
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Distillation Method ◽  
Relative Standard ◽  
Tobacco Sample ◽  
Automated Determination

AbstractA procedure for the automated determination of ammonia in tobacco has been developed. Ammonia is extracted from the ground tobacco sample with water and is determined with a Technicon Auto Analyser system which employs separation of the ammonia through volatilization followed by colourimetry using the phenate-hypochlorite reaction. The procedure has been applied to a variety of tobaccos containing from 0.02 to 0.5 % ammonia with an overall relative standard deviation of 2 %. The accuracy of the procedure as judged by recovery tests and by comparison to a manual distillation method is considered adequate

scholarly journals Indirect and Direct Determination of the Casein Content of Milk by Kjeldahl Nitrogen Analysis: Collaborative Study

1998 ◽  
Vol 81 (4) ◽  
pp. 763-774 ◽  
Author(s):  
Joanna M Lynch ◽  
David M Barbano ◽  
J Richard Fleming
Keyword(s):  
Standard Deviation ◽  
Nitrogen Content ◽  
Relative Standard Deviation ◽  
Collaborative Study ◽  
Direct Determination ◽  
Raw Milk ◽  
Method Performance ◽  
Relative Standard ◽  
Milk Casein

Abstract The classic method for determination of milk casein is based on precipitation of casein at pH 4.6. Precipitated milk casein is removed by filtration and the nitrogen content of either the precipitate (direct casein method) or filtrate (noncasein nitrogen; NCN) is determined by Kjeldahl analysis. For the indirect casein method, milk total nitrogen (TN; Method 991.20) is also determined and casein is calculated as TN minus NCN. Ten laboratories tested 9 pairs of blind duplicate raw milk materials with a casein range of 2.42- 3.05℅ by both the direct and indirect casein methods. Statistical performance expressed in protein equivalents (nitrogen ⨯ 6.38) with invalid and outlier data removed was as follows: NCN method (wt%), mean = 0.762, sr = 0.010, SR = 0.016, repeatability relative standard deviation (RSDr) = 1.287℅, reproducibility relative standard deviation (RSDR) = 2.146%; indirect casein method (wt℅), mean = 2.585, repeatability = 0.015, reproducibility = 0.022, RSDr = 0.560℅, RSDR = 0.841; direct casein method (wt℅), mean = 2.575, sr = 0.015, sR = 0.025, RSDr = 0.597℅, RSDR = 0.988℅. Method performance was acceptable and comparable to similar Kjeldahl methods for determining nitrogen content of milk (Methods 991.20, 991.21,991.22, 991.23). The direct casein, indirect casein, and noncasein nitrogen methods have been adopted by AOAC INTERNATIONAL.

Determination of Nitrate in Water by HPLC

2013 ◽  
Vol 448-453 ◽  
pp. 406-408
Author(s):  
Jing Liu ◽  
Xiao Na Ji ◽  
Qing Kai Ren ◽  
Sheng Shu Ai ◽  
Li Jun Wan ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Recovery Rate ◽  
High Performance ◽  
Separation Efficiency ◽  
Fast Analysis ◽  
Relative Standard

We established a method fordetermination of nitrate in water by High Performance Liquid Chromatography(HPLC). The sample was analysed by HPLC-ADA and was quantitated by externalstandard method after being simply processed. This methd has the advantages ofhigh separation efficiency and fast analysis. The experiment result showed thatthe linearly dependent coefficient was0.994, the recovery rate was between 98.7%～105.7%,the relative standard deviation（RSD）wasless than 2.1 %, and the lowest detectable limit is 0.01ng (S/N=1.6).

scholarly journals Development and validation of spectrophotometric method for phenylephrine hydrochloride estimation in nasal drops formulations

2008 ◽  
Vol 27 (2) ◽  
pp. 149 ◽  
Author(s):  
Ivana Savić ◽  
Goran Nikolić ◽  
Vladimir Banković
Keyword(s):  
Standard Deviation ◽  
Sodium Hydroxide ◽  
Relative Standard Deviation ◽  
Spectrophotometric Method ◽  
Molar Absorptivity ◽  
Dosage Forms ◽  
Phenylephrine Hydrochloride ◽  
Relative Standard ◽  
Development And Validation

Simple, accurate and reproducible UV-spectrophotometric method was developed and validated for the estimation of phenylephrine hydrochloride in pharmaceutical nasal drops formulations. Phenylephrine hydrochloride was estimated at 291 nm in 1 mol⋅dm-3 sodium hydroxide (pH 13.5). Beer’s law was obeyed in the concentration range of 10–100 μg⋅cm−3 (r2 = 0.9990) in the sodium hydroxide medium. The apparent molar absorptivity was found to be 1.63×103 dm3⋅mol−1⋅cm−1. The method was tested and validated for various parameters according to the ICH (International Conference on Harmonization) guidelines. The detection and quantitation limits were found to be 0.892 and 2.969 μg⋅cm−3, respectively. The proposed method was successfully applied for the determination of phenylephrine hydrochloride in pharmaceutical nasal drops formulations. The results demonstrated that the procedure is accurate, precise and reproducible (relative standard deviation < 1 %), while being simple, cheap and less time consuming, and hence can be suitably applied for the estimation of phenylephrine hydrochloride in different dosage forms.

scholarly journals Badanie stabilności barwnych znaczników fluorescencyjnych w silnie zasiarczonych wodach złożowych

Nafta-Gaz ◽  
2021 ◽  
Vol 77 (2) ◽  
pp. 82-91
Author(s):  
Katarzyna Wojtowicz ◽  
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Rhodamine B ◽  
Water Reservoir ◽  
Distilled Water ◽  
Test Results ◽  
Fluorescent Tracers ◽  
Reservoir Water ◽  
Relative Standard

The article presents the issues related to the determination of colored fluorescent tracers such as fluorescein, eosin yellowish, rhodamine B and uranine in reservoir waters by spectrophotometric method. For this purpose, the influence of the pH of the solution on the absorption spectra of the tested tracers was checked. Test results show that fluorescein, rhodamine B and uranine are sensitive to changes in the buffer pH, therefore it is advisable to use stable tracer solutions as well as to control and possibly correct pH in further tests. As part of the study, calibration curves of fluorescein, eosin yellowish, rhodamine B and uranine in distilled water, reservoir water A4 and highly sulfated reservoir waters A5 and A6 were plotted and the analytical methods were validated. Analytical validation included determination of linearity, standard deviation and relative standard deviation of the tested tracers solutions. High values of the regression parameters (0.9927–0.9998) of the analyzed tracers prove a good linear fit, while low values of standard deviation and relative standard deviation prove its repeatability and precision. Particular attention was paid to testing the stability of colored fluorescent tracers in highly sulfated reservoir waters. For this purpose, solutions of the tested tracers were prepared at concentrations of 10 mg/dm3 in distilled water, A4 reservoir water and highly sulfated A5 and A6 reservoir waters. Measurements of the tested tracers in the prepared solutions were performed every 2 days over the period of 1 month. The test results show that fluorescein, eosin yellowish, rhodamine B and uranine solutions are stable in the distilled water and A4 reservoir water, while they degrade in the A5 and A6 reservoir waters. Fluorescein and uranine turned out to be the most sensitive, as they degraded completely in the A6 reservoir water after 20 (fluorescein) and 22 (uranine) days. Yellowish eosin and rhodamine B turned out to be slightly more stable in highly sulfated reservoir waters, as they degraded completely in the A6 reservoir water after 24 days.

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